Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

finishing.com -- The Home Page of the Finishing Industry

The authoritative public forum
for Metal Finishing since 1989
-----

Phosphoric acid anodize, why can't I rework more than once?

Our specification for Phosphoric acid anodizing in preparation for adhesive bonding is similar to a large aerospace manufacturer's. Both indicate that items can not be stripped and re-anodized more than once (regardless if it is clad or bare aluminum). Why is this? Do additional rework cycles adversely affect the bonding characteristics of the anodize (and how)?

Terry L. Warner
- Elmira, New York

I think the reason would be primarily dimensional, Terry.. Remember that anodizing is not like painting or plating where material is added to the surface. Rather, in anodizing the anodized film is formed from the aluminum substrate; when you strip it you are left with thinner aluminum than you started with. If you built and stripped two anodized films, then built a third film, the remaining base metal would probably be too thin.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: